High Density Die Casting (HDDC) is a process developed by Aavid with its University partners to manufacture near net shape parts with better mechanical and thermal properties compared to die castings.
It is particularly well suited to making high performance heat sinks and liquid cold plates using aluminum alloys with high thermal conductivity. New process controls during solidification enable fine grain structure with near zero porosity.
Embedded InsertsAluminum, copper, graphite or other solids with lower CTE than Aluminum can be embedded directly into the part. The process yields a strong mechanical bond with almost no interfacial gap or porosity.
Thin and High Aspect Ratio FinsSmaller minimum enclosure wall thickness, smaller minimum fin spacing, fin thickness and
draft angles result in higher cooling fin densities and lighter enclosures.
Enhanced Post Forming ProcessesMachining without exposing porosity, brazing, and porosity free welding processes enable
leak tight complex assemblies. Wet surface finishing processes like anodizing and electroplating can
be done without electrolyte retention in surface porosity.
Die Cast vs. HDDC comparison for 40-60mm tall finned heat sinks
|Fin Geometry (Plate, pin, embedded etc.)||All Types||All Types|
|Minimum enclosure wall thickness (mm)||2-4||1.5-3.5|
|Minimum fin to fin spacing (mm)||5||3-4|
|Minimum fin tip thickness (mm)||2.5-3.0||1.0-1.5 plate fin; 2.0 pin fin|
|Minimum fin tamper angle (degree)||1.0-1.5||1.0|
|3D near net shape rating ( 5 is best )||5||4|
|Surface quality rating (5 is best)||2||4|
|Leak tight rating (5 is best)||2||5|
|Aluminum Alloys||ADC 10-12 or 3xxx||1xxx, 6xxx, 3xxx|
|Thermal Conductivity (W/m K)||90-120||190-240|
|Porosity (%) and Grain Structure|| 3-7|| 0|